For the past two years, Oprah admits she's taken her health for granted. "I didn't appreciate what this body has done for me," she says. After falling off the weight loss wagon and gaining 40 pounds, Oprah says she had a wake-up call that made her thankful for every part of her body—from the tip of her toes to the top of her head.

"I am so grateful for everything. My bones for carrying me. My heart for beating. My lungs for pumping air," she says. "You need to love yourself enough to know that you being healthy is worth it."

Oprah hopes everyone will make 2009 the year they put themselves back on their to-do lists. To help you get started, Dr. Oz is sharing his Ultimate Health Checklist, a complete guide to health and wellness. He's here to tell you what to eat, what to avoid and which medical tests could save your life.

Think it's too late to take control of your health? Laura Plummer, a past guest, is proof that it's never too late. When Oprah and Dr. Oz first met Laura in February 2008, this 44-year-old mother was an avid smoker who didn't exercise. She also admitted that stress was taking a toll on her emotional and physical health.

Dr. Oz and his partner, Dr. Michael Roizen of the internationally renowned Cleveland Clinic, asked Laura to take a Real Age test, which helps patients understand how their lifestyle choices can affect their life expectancy. The results were shocking. Though Laura was just 44 years old, the test said she was closer to 60. The good news? Dr. Oz told Laura she could turn her life around by kicking her smoking habit and making better choices.

"I certainly don't want my body to be that old. I don't want my mind to be that old. I don't want my lungs to be that old. I just want to be 44," Laura said. "It's the beginning of my journey—my journey on to health and fitness and feeling good and being 44 instead of 60. This is the start."